a little light reading

We love bringing a great deal on any kind of lighting supplies to our customers, and gladly broke the $10 mark on a quality BR30 LED in the last couple of months.

We're talking about a name brand -- TCP -- and we're talking about the highest CRI rating you're likely to find on an LED bulb. (This is its ability to render colors well.) We did a lot of digging, and think it may be the best value in BR30 LEDs out there.

But it looks like we weren't ready to stop there -- for a limited time, and while supplies last, we've made a great deal unbeatable by slashing another 20% off the price. Through June 11 or until we're out of stock, these bulbs are just $7.95.

Seriously, it is now time to relamp your home or office with LEDs. This option gives you an incredibly affordable option when choosing a quality bulb. But act quickly before they're gone.

First, consider rapid start and programmed rapid start as similar technologies. The first is used by older magnetic ballasts while the latter is a more refined version used by modern electronic ballasts. Both types effectively ramp up the voltage on a lamp to light it. This is a relatively "gentle" approach to getting it lit, and preserves the rated life of the lamp. It doesn't provide an "instant on" experience, but still provides light soon after the switch is turned on. These types of ballasts can be used in areas using occupancy sensors, or anywhere lights are frequently turned on and off.

Instant start ballast technology sends a more powerful, immediate surge of voltage to provide immediate light. But the power of the surge is a jolt to the lamp and can shorten its rated life if used too often, so this technology is generally used where lights will not be turned on and off frequently. Once the lights are on, this technology is more efficient than the other two, so it helps to reduce energy costs.

With so many advances in the world of LEDs, we thought we'd take time to update some of the old data online comparing this digital technology with the non-digital technologies of CFL and incandescent bulbs. This seems especially useful now that your average household incandescent has been phased out of production and importation, and many people have found that CFL bulbs don't last as long as they were first promoted to.

Let's first touch on that point of CFLs: many packages originally said they would last (or have an average rated life of) 10,000 hours. However, this is under conditions that take advantage of how they work, which means using them in areas where they're typically left on at least 15 minutes at a time. In frequent "on/off" locations like bathrooms or closets, their lifespan could drop dramatically. CFLs also don't come on to full brightness right away, most don't dim, and most don't work well in the cold.

Having said this, they were an important option when people were starting to look for energy savings from their light bulbs, as they use only about 25% of the energy consumed by incandescent bulbs. Usually for $5 or less (some years ago), you could replace your 50 cent incandescent bulb with something that would last 10 times as long (in fact more like 5 to 10 times as long), so the cost of the bulbs themselves evened out. Meanwhile, you would slash your energy bill.

Given that lighting makes up about 10% to 15% of a residential electric bill when you're using incandescent bulbs, this could cut electric bills by roughly 8% to 11%. And while LEDs in the early days were slightly more efficient than CFLs, they also cost around $20 to $40 per bulb and most people couldn't afford them.

But that's no longer the case, so now let's get an update on the world of LEDs.

A Review of Today's LED Bulbs

Today, CFL bulbs have continued to plummet in prices and you can sometimes pick them up for around $1 each. But meanwhile, LED bulbs have become affordable as well with prices ranging from $3 to $10 (depending on the quality and features) for household (A19) replacement bulbs. Or if you spent more, you could get "smart" LED bulbs, but that's a topic for another day.

Meanwhile, the efficacy of LEDs has continued to improve. This means they're producing more light, or lumens, for every watt of energy used. For instance, you can replace a 60-watt incandescent bulb with a 13 or 14-watt CFL -- an efficacy of up to about 60. Early LEDs had a similar efficacy, and may have only saved you 1 watt in a 60-watt replacement.

But today's LEDs, while far lower in cost, have boosted their efficacy and now approach 100. This means you can save up to 4 or 5 watts per bulb. If this doesn't seem like much, keep in mind that the average light bulb is used for around 1.6 hours per day, or 500+ hours per year, and this difference could yield $3 to $4 in energy savings each year. So an LED could pay for itself against a CFL within 1-2 years and then start keeping money in your pocket every year after that. Not bad for a technology that may last you 20 years!

Plus, LED efficacy is expected to continue rising, and to reach around 150 by 2020.

Even better, the quality of LEDs continues improving as well. Today, some LED bulbs approach a 100 CRI, which means they score almost perfectly on the Color Rendering Index. (This is a complex topic, however, as different technologies render colors differently, even if scoring a similar number on this scale.)

Meanwhile, some LED technology now make the bulbs even more closely mimic incandescent bulbs, which provide a warm color that many people love. This new technology means that the bulbs not only mimic the color temperature of incandescent bulbs at full brightness, but they also get warmer -- like incandescent bulbs do -- when dimmed.

CFL

LED

Average Watts to Replace 60W Incandescent Bulb

13-14

8-10

Average Life

Up to 10,000 Hours

10,000 to 25,000 Hours

Instant On

No

Yes

Dimmable

Usually No

Usually Yes, on Compatible Dimmers

Durable

No

Yes

Made for Frequent On / Off

No

Yes

Comes in Many Color Temperatures

Yes

Yes

Works Well in the Cold

No

Yes

Smart Bulbs Available

No

Yes

Emits UV

Yes

Little to None

Contains Mercury

Yes

No

​A Summary of CFLs and LEDs

For a while, then, CFLs were by far the more affordable energy saving light bulb, and although they had their drawbacks, they were the obvious incandescent replacement bulb of choice. Today, however, LEDs are affordable, distinctly more energy efficient than CFLs, and have a number of benefits including cold weather usage, immediate full brightness, a substantially longer life, and more.

So today, the choice between CFLs and LEDs has less to do with initial cost than it once did, and rests far more in the hands of personal preference. Either way, they represent an easy way to dramatically lower your electricity bill.

Last week, Tesla Motors took a step into being more than just a car company by announcing their residential Powerwall Battery. And it's been met by both fans and skeptics. Our goal here isn't to decide whether this is a game changer or a dud, but to look briefly at how the battery works as a backup power source and how this relates to the transition from incandescent to LED lighting.

The Tesla Powerwall and Solar Panels

We'll point out first that a primary market for this battery seems to be those with solar panels, or solar systems, installed on their homes. In this case, the battery isn't so much an emergency backup battery for the house (though potentially also a backup). Instead, it's a way to store solar energy during the day so it can continue being used at night, extending the value of solar power. We'll leave the details of this, however, to solar experts.

The Tesla Powerwall as a Rate Reducer

Another suggested use for the Powerwall is for those with different energy costs at different times of the day. Residential users of DTE Energy at the time of this writing, for instance, can stick with a standard rate system or -- if they feel they can push most of their energy use to the hours of 7 p.m. to 11 a.m. -- they can choose to pay on-peak and off-peak rates.

In broad brush strokes, if someone chose to do that and somehow pushed all of their energy use to those hours, they could save approximately 2.3 cents per kWh when compared to the traditional rates, saving approximately $20/month in the average home (using just over 900 kWh per month).

Most people could never push all their energy use to between the hours of 7 p.m. and 11 a.m., but with the Powerwall, you could store up 10 kWh during off-peak hours and use them on peak at the lower rate. So if you could limit your daytime use of energy (when many people are at work anyway) to 1/3 of your overall use (assuming 30 kWh per day), then you could fully live on "off-peak" energy rates.

(We should mention that these numbers are really for painting a general picture, and don't take into account things like lost efficiencies of storing and then using the off-peak power.)

Of course this $20 monthly savings comes at the cost of a battery that's roughly $7000 installed. So the Powerwall would have to offer more value than these savings alone. And that's where it comes in as a backup power source.

The Tesla Powerwall as a Backup Battery

The final selling point of the Powerwall is as a backup battery for the entire home. If the power grid goes down, you have up to 10 kWh of energy stored up that you can keep using. Let's get one thing out of the way quickly: central air would eat that up in about 3 hours of use. And an electric heater? Forget about it. But if you've got a gas furnace or shut off your AC when the grid goes down, you could potentially run your house as normal for 6-8 hours. And if you adapted to the need, reducing energy consumption as much as possible, you could extend that substantially. And this is where efficiency in the home -- including lighting -- becomes especially important.

We've already said that air conditioning would have to be turned off. After AC, refrigerators and lighting are the two biggest energy users in the typical home. Based on our research, we've found numbers ranging from 2 to 6 kWh of energy used each day by refrigerators, suspecting that 2-4 is accurate in most cases.

Meanwhile, according to this excellent resource, the typical American household runs about 60 lamps [bulbs] at 1.6 hours a day and at an average wattage of 47.7. (This depends on the time of year, location in the country, and more.) At these numbers, a household's lighting use draws 4.6 kWh per day. Considering a 10 kWh Tesla Powerwall as backup … ouch.

But many of our homes have not yet converted to LED. If we expect that 47.7 average watts in a home includes mostly 60 watt incandescent bulbs along with some at 25 and 40 watts, then a transition to LED lighting could reduce the average wattage from 47.7 to about 8. This then reduces a home's lighting energy use to about .8 kWh per day.

(Likewise, this speaks to the value of more efficient refrigerators and other appliances in the home.)

If you were to limit household energy use during a power outage to refrigeration, some lighting, a couple computers, and a little cooking, you might last a single day on a 10 kWh Powerwall with incandescent lighting; you might last two days if you had switched to LED lighting.

Even without a Powerwall, switching to LED lighting in the example above would save many homes $15 or more per month. Given the Powerwall investment of $7000 to save $20/month, this is a much easier investment -- at Lighting Supply prices, you could replace the 60 bulbs in an average home for $400 to $600 while getting name brand bulbs. (We recommend trusted brands for consistent colors and better quality when it comes to LED.) Those bulbs would pay for themselves in just a couple years … something Powerwall can't really say for itself.

The Skeptic's Look at Powerwall as a Backup Battery

A final thought on the Tesla Powerwall as a backup battery. First, this function is complicated by the other two functions described above. If you're using the Powerwall to carry daytime (solar) energy into the night, or off-peak energy rates into on-peak hours, then you may already be using some or even much of the stored power. So if the grid power goes out at the wrong time, you could have little left to keep your home running. Because of this, if you're using the Powerwall mainly as a backup power source, it may not make sense to also use it for its other purposes.

Some skeptics of the Powerwall have also pointed out that, for $7000, you could get a pretty nice generator powered by natural gas to keep your entire home running regardless of how long the power was out. We don't know what drawbacks that may have, or the costs of maintenance, but this is another point to consider.

So these are our thoughts on the new Tesla Powerwall and one more reason why it's such a good idea to switch to LED lighting. Do you have more information on the Powerwall that should be considered here? Are you for it, against it, or just don't care? We'd love to hear your thoughts on any of what was discussed here.